Old railroad beds will often have too much material on each side of the track so that the track will be more or less in a trench, which will obstruct the drainage. The material itself has also often a bad draining capacity. The allowed axle load is often 22 tonnes for old railroad beds whereas an axle load of for example 30 tonnes can be allowed on a perfect railroad bed. Old railroad beds may also allow a higher axle load if their parts outside of the track are regraded (including removal of excess material). If new macadam must be replaced for a part of the old material, it is often possible to remove the material, screen it and replace a coarse part of it.
There are often cables embedded at the side of the track and they are sometimes in tubes or hoses. They should nowadays normally be at a depth of one meter but they are often closer to the surface in old roadbeds. Usually, ordinary bucket excavators are used to remove the excess material and, in order not to damage the cables, a man with a manual worktool, for example a pick axe, must aid in the excavation. This operation is costly and time consuming and still, the risk of damaging the cables is not eliminated.